package cn.edu.hadoop;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

import java.io.IOException;

public class WordCountCombiner extends Reducer<Text, IntWritable,Text,IntWritable> {
    @Override
    protected void reduce(Text key,Iterable<IntWritable> values,Reducer<Text,IntWritable,Text,IntWritable>.Context context) throws IOException,InterruptedException{
//        对数据进行局部汇总
        int count = 0;
        for(IntWritable v:values){
            count += v.get();
        }
        context.write(key, new IntWritable(count));
    }
}
